Apparatus for drilling in earth covered rock



25, 1966 B. R. GENBERG ETAL 3,231,032

APPARATUS FOR. DRILLING IN EARTH COVERED ROCK 3 Sheets-Sheet 1 FiledApril 5, 1960 lNV T05 I -,I 1

TTORNEY Jan. 25, 1966 GENBERG A 3,231,632

APPARATUS FOR. DRILLING IN EARTH COVERED ROCK Filed April 5, 1960 3Sheets-Sheet 2 !NVENTOR.$

, ATTORNEY Jan. 25, 1966 R GENBERG ETAL 3,231,032

APPARATUS FOR. DRILLING IN EARTH COVERED ROCK Filed April 5, 1960 sSheets-Sheet :5

- INYENTORJ .ATTORNEY United States Patent O 3 ,032 APPARATUS FORDRILLING IN EARTH COVERED ROCK Bengt Rune Genherg, Norrkoping', JohnAnders Hialsten, Sandviken, and Carl 010v Lindgren, Nacka, fiweden,assignors to Atlas Copco Aktiebolag, Nacka, Sweden,

a corporation of Sweden Filed Apr. 5, 1960, Ser. No. 23,120 11 Claims.(Cl. 175-171) This invention relates to apparatus for drilling in earthcovered rock. For various purposes it desirableto be able to drill rockwithout first removing the soilcap which often covers the rock. Theapparatus according to the present invention may be used in connectionwith building of water ways, harbors, water power plant d ains andcanals, geological investigations, stabilizing of ground and injectionof cement or other material in the ground, in rock or in darnstructures, piling for building structures, and for other work. Diamonddrills and percussion drills of various types have been suggested forwork of the above type but have proved expensive or slow in operation.One object of the invention is to provide an apparatus for the abovepurpose which is capable v of penetrating an earth layer of very varyingcomposition which may contain hard clay, moraine, boulders, more or lesssolid rock or the like. The apparatus according to the inventionprovides a means for drilling through such an earth layer down to andinto the underlying rock and for obtaining a clean hole all the way downwhich may be charged for blasting the rock and any large boulders orstiff earth layers covering the rock or used for other purposes, forinstance for taking out samples of the ground or rock, for anchoringpiles, for injection of cement or other stabilizing material or thelike.

Other and more detailed objectsof the invention and the severaladvantageous ways of carrying the invention into effect and achievingthe advantages of its use will appear more fully as the ensuing portionof this specification proceeds.

In the accompanying drawings forming a part hereof one suitableembodiment of apparatus for carrying the invent-ion into effect is shownby way of example, but without limitation, it being understood that theinvention may be modified both as to apparatus and the method ofutilizing the apparatus within the scope of the appended claims definingthe invention.

In the drawings:

FIG. 1 is a side elevation of apparatus embodying the invention .partlybroken away in order to make possible the illustration of the completeapparatus on one sheet of drawing. FIG. 2 is a vertical section partlybroken away of a completed hole through earth and a boulder and in theunderlying rock. FIG. 3 is a vertical longitudinal section on a largerscale of a drill forming a part of the apparatus according to FIG. 1 andFIG. 4 is a longitudinal section of an adapter and of a drill rod anddrill tube assembly used in connection with an apparatus of FIG. 1. FIG.5 is a detail cross section on line VV in FIG. 3, and FIG. 6 is a crosssection on line VIVI in FIG. 3. FIG. 7 is a section on line VII-VII inFIG. 3, and FIG. 8 is a section on line VIIIVIII in FIG. 4.

In FIGS. 1 and 2 numeral 1 indicates the upper surfaceof the soilcapcovering a rock formation 2 which may have any irregular contour. It issometimes convenient before starting a drilling operation with theapparatus according to the invention to remove a suitable part of thesoilcap with conventional earth removing machines and to plane theearth, if desired, with bulldozers or other suitable machines to providea fairly even surface on which the apparatus according to the inventionmay be mounted in a convenient manner according to the conice ditions ofthe work and the depth and number of holes to be drilled. Naturally,such preparations of the ground are usually not necessary when the holesto be drilled are far apart, or when it is not desired to remove thesoil as, for instance, in connection 'with investigation drilling andvarious types of injection drilling.

The illustrated apparatus is an example of an apparatus 'used fordrilling in connection with the building of a canal. The upper part 3 ofthe soilcap may consist of comparatively soft ground and the deeperportions 4 may consist of hard clay or moraine which may contain largeboulders as indicated at 5 FIG. 2. It also often occurs that the rockcove-red by the earth is of a very poor quality so that it is necessaryto drill down through loose rock a considerable distance before thesolid rock is encountered.

The illustrated apparatus consists of a number of steel channels 6provide on the ground parallel to each other and forming a track onwhich a frame '7 of suitable steel channels is movable on wheels 8. Thetransverse members of the frame 7 form a track for a frame 9 which ismovable on wheels 10 on the frame ,7 perpendicular to the direction inwhich the frame 7 is movable on the channel 6. The frame 9 carries adrill post comprising a drill guide and feed structure which isgenerally indicated by it and which may consist of 2 parallel steelchannels 12 welded together with longitudinal steel members 13 by meansof transverse stiifeners or webs 14 to form the rigid drill post, thelength of which may, for instance, substantially be the same as thedesired depth of the holes to be drilled. The drill post 11 is pivotallysupported in a suitable way as at 15 on the frame and two steel strutsof suitable frame work 16 are provided for supporting the drill post 11about halfway from the frame 9 to the top. The struts 16 may preferablybe hingedly connected to a bracket 17 on the a drill post by bolts 18and to two brackets 1d clamped to the opposite side members of the frame9 by suitable screw clamps 20, the brackets 19 supporting the members 16by means of bolts 21. The drill post it carries a drill feed motor 22which may consist of a reversible pneumatic motor supplied withcompressed air through a hose 23 and containing a driving sprocket wheel:24 for a drill feed chain 25 which is car-- ried over the sprocketwheel 24, idlers 26 in the feed motor housing, and over large idlerwheels 27 and 28 at the bottom and top of the drill post 11, One of saididle sprocket wheels, preferably the wheel 27 may be provided with meansfor tensioning the chain 25 which means are well known in the art andare therefore not illustrated. The chain 25 is connected to a slide 2?which .is movable on the flanges 30 of the channels 12 forming a part ofthe drill post.

The slide '29 carries a percussion drill comprising a percussion motor31 and a reversible separate drill steel rota tion' motor 32. Thepercussion motor is provided with compressed air through a hose 33 andwith flushing water through a'hose 34- and the rotation motor isprovided with compressed air for ahead and reverse rotation through twohoses 35. The percussion motor 31 contains in conventional manner acylinder 36 accommodating a hammer piston 37 the reciprocation of whichis controlled by a distributing valve 38 in the back head 39 of themotor in conventional manner. A conventional rifle bar 49 cooperateswith a rifle nut 41 in the piston 37 to rotate the piston in order toavoid uneven wearing of the piston. The cylinder 36 is clamped togetherwith a chuck casing 42 by means of side bolts 43 and the chuck casing 42and cylinder 36 are rigidly secured to the slide 29 The chuck casingcontains a front bushing 44 and rear bushings 45, 46 in which an adapter47 is mounted with cylindrical portions '48 and 49, respectively. Theadapter 47 is rotatable in the rear bushings 45, 46 and has anintermediate portion 58 between the cylindrical portions 48, 49 ofnon-circular cross section, for instance as obvious from FIG. 5, whichfits into a chuck 51 rotatably mounted in the chuck casing 42. The chuck51 has a non-cylindrical bore 52 through which the intermediate portion50 is axially slidable but non-rotatable. The bushing 44 is providedwith an opening 53 through which the portion 58 is axially slidable andwhich may .be made to register with the opening 52 by suitable turningof the bushing 44. A lock nut 54 is screw threaded on the chuck 51 at 55and the bushing 44 has projections or claws 57 cooperating with recesses56in the chuck 51 so that upon tightening of the nut 54 the bushing 44may be locked in a position in which the opening 53 does not registerwith the opening 52. The bushing 44 thereby prevents the adapter 47 frombeing removed from the chuck 51. The portion 58 of the adapter forms arear shoulder 58 and a front shoulder 59 cooperating with correspondingshoulders 60 on the bushing 45 and 61 on the bushing 44 and permittingaxial forces to be transmitted from the feeding motor through the drillto the adapter for feeding or retraction of the drill rod assembly,respectively. Flushing water is supplied through the adapter through aflushing water tube 62 extending into a flushing water passage 63 in theadapter and sealed in the adapter by a suitable packing 64 so that ahigh flushing water pressure may be maintained. The hose 34 is connectedto the flushing Water tube 62 in conventional manner.

For rotation of the chuck 51 and the adapter 47 the chuck carries asprocket wheel 65 driven by a chain 66 from a driving sprocket wheel 67provided on a shaft 68 mounted in bearings in a casing 69 which containsa reduction gear transmission 70 driven by a reversible compressed airoperated motor 32. The casing 69 is carried by a housing 71 forming apart of the chuck casing 42 and covered at the front end by a removablecover 72 which upon removal allows inspection and adjustment of thechain transmission 65, 66, 67. The chain 66 is carried over an idlesprocket wheel 73 mounted on a shaft 74 carried by a slide 75 which bymeans of a nut 76 may be adjusted in order to adjust the tension of thechain 66. The illustrated design makes it possible to replace thesprocket wheels 65 or 67 by other sprocket wheels in order to change thetransmission ratio or the torque or speed of rotation of the chuck.

The drill rod assembly consists of the adapter 47 and a train of drillrods 77 provided with externally screw threaded ends with rounded screwthreads and coupled together by means of coupling sleeves 78 providedwith correspondingly rounded screw threads 79, said type of screwthreads being commercially known under the trademark Rope Thread. Theadapter 47 provides a socket 80 which is provided with internal roundedscrew threads as obvious from FIG. 4 to fit the end of a drill rod 77.

A drill bit 81 provided with hard metal inserts and with a screwthreaded shank 82 is connected to the extreme drill rod 77 by a similarcoupling sleeve 78 having rounded screw threads. A train of drill tubes83 is connected by means of sleeves 84 to each other and by means of asleeve 85 to the adapter 47 and at the lower end of said train of tubesan annular drill bit 86 having a sleeve portion 87 is screw threaded onto the lower end of the extreme drill tube 83. The drill tubes 83 areprovided with screw threaded ends 88 with rounded screw threads of thetype known under the trademark Rope Thread and the engaging sleeves 85,84 and 87 are threaded correspondingly. The sleeve 85 has a screwthreaded portion 89 which may be of the same type but which isillustrated as a trapezoid screw thread engaging a corresponding screwthread on the outside of the socket 88 formed by the adapter 47. Thesleeve 85 has a hexagonal external grip portion 91 and the rods 77 areprovided with flats 92 close to the screw threaded ends tofacilitateturning of municating with the passage 63 in the adapter 47 andterminating in flushing medium openings 94 in the central bit 81.

The percussion waves produced by the hammer piston 3'7 are transmittedto the adapter 47 and through a shoulder 95 in the socket end of theadapter to the end face 96 of the rear drill rod 77, further through thedrill rods over the abutting end faces 98 of the various drill rods ofthe drill rod train and through the end face 99 of the drill bit bitshank 82 to the ground or rock. Furthermore, the percussion wavestransmitted to the adapter'are transmitted through shoulders 180 on theadapter through an internal flange 101 of the sleeve 85 to the flat endface 182 of the drill tube inserted in the sleeve 85 and further throughthe drill tubes and abutting end faces 183 of said tubes to a shoulder104 in the ring drill bit 86 and through said bit to the ground or rock.

In order to facilitate handling of the apparatus according to theinvention a control panel 105 is provided on the drill post 11 andfurthermore an air hoist 106 provided with a cable 107 carried over awheel 188 at the top of the drill post is provided for manipulating thedrill tubes when it is not desired or convenient to use the feedingmotor for this purpose. Said hoist may, of course, also be used duringthe erection of the drill post and when the drill post is taken down.Through a hose 189 compressed air is supplied to the hoist motor 186.The control panel 105 carries control valves not illustrated in thedrawing and operated by handles 110, 111, 112, 113 and 114 controllingthe reversible feed motor 22, the percussion motor 31, the flushingwater, the reversible rotation motor 32 and the hoist 186.

Drilling of earth covered rock with the apparatus according to theinvention is carried out in the following manner:

According to the condition of the ground and the depth of the earthlayer on the rock one or more drill rods and a corresponding number ofdrill tubes are assembled with the central drill bit and the ring drillbit and with the adapter 47, the central drill bit 81 preferablyextending a short distance ahead of the ring drill bit 86. The combinedtrain of drill rods and drill tubes are forced down through the earth bymeans of the feeding motor 22 and with the rotation motor 32 inoperation and flushing water turned on through the train of drill rods.When hard ground, a boulder or rock is encountered the percussion motor31 is started and operated. When the assembled train has been drivendown as long as possible, the .percussion motor and the rotation motorare stopped and flushing is interrupted and the sleeve 85 is uncoupledfrom the uppermost drill tube 83. The uppermost drill rod 77 is grippedby means of a suitable wrench so as to prevent it from turning and therotation motor 32 is reversed which unscrews the adapter from theuppermost drill rod 77. The drill is then retracted a suitable distanceby means of the feeding motor 22. A sleeve 78 and a further drill rod 77are screwed unto the end of the previously uppermost drill rod 77 and asection of the drill tube 83 with a pertaining sleeve 84 is slipped overthe drill rod and coupled together with the uppermost drill tube 83. Bymeans of the feeding motor 22 the adapter 47 is then again lowered andthe uppermost drill tube 83 is connected to the socket 8t) and thesleeve 85 by rotating the rotation motor 32 in ahead direction. Drillingmay then be continued with the central drill bit and the ring drill bitas before. The above procedure is continued until the assembled trainsof drill bits and rods and tubes has started to penetrate the rock 2below the loose ground. Drilling is'then usually continued until thering drill bit has entered the solid rock a short distance, as indicatedin FIG. 1 and at 115 inFIG. 1. When the ring drill bit 86 has enteredthe solid rock, for instance 5-10 inches, the

drill is stopped and the sleeve 85 is uncoupled from the adapter 47 byloosening the trapezoid screw threads at 89.

The train of drill rods may then be lifted by means of the feed motor 22and a further drill rod may be assembled and drilling continued by meansof the central drill bit 81 only as indicated at 116 in FIG. 1, and suchdrilling is continued until it is obvious that the material encounteredis the solid rock and not only a large boulder or the like.

When the hole 116 has reached the desired depth, the train of drill rods77 and the central bit 81 are lifted by means of the feeding motor 22which is then reversed. The train of drill tubes 83 is, however, left inthe hole to protect the hole against earth and other material that wouldbe likely to fill the hole. A smooth clean hole is now available allthrough the train of drill tubes 83 to the bottom of the hole 116drilled by means of the central drill bit 81. A tube 117 of artificialresin or other cheap material and provided with a simple sealing ring113 close to its lower end is pushed down through the train of tubes 83into the hole 116 where the sealing ring 118 forms a seal with the wallsof the hole 116 preventing sand and clay et cetera from entering thedrill hole. When the tube 117 has been safely anchored in this way thecable 107 may be attached to the upper end or slide d0 of the train ofdrill tubes 83 in any suitable manner and the hoist 106 is then operatedto pull the train of drill tubes 83 out of the ground leaving theplastic tube 117 or the like in the ground to provide a suitable holefor the provision of a charge of dynamite or other explosive. When ahole has been completed in this way, as illustrated in FIG. 2, the wholedrill rig is moved to the next position on the wheels It? or 8 as thecase may be, whereupon drilling is continued as hereinabove described.

While the invention has been described above in connection with a drillrig for drilling a large number of holes over a considerable area, amore conventional drill rig, or a conventional drillcarriage maynaturally be used where ground conditions permit movement of such adrill rig or carriage over the ground and where the number of holes islimited. When it is desired to make ground investigation, samplecollectors or other instruments may be carried down through the train ofdrill tubes when the central drill bit and the drill rods have beenremoved. The provision of plastic or other simple cheap tubes in theholes is only used when it isdesired to blast the holes. Furthermodifications of the invention may be made within the scope of thefollowing claims according to the prevailing conditions of the work tobe carried out.

What we claim is:

1. In apparatus for drilling in earth covered rock with both a hollowdrill tube and a drill rod coaxially operating within said drill tubeand with both said drill tube and drill rod being driven for both rotaryand axial percussive drilling movements, the combination which comprisespercussion motor means for providing said axial percussive drillingmovement, means for supporting said motor means for axial advancing andretracting movements toward and away from said earth covered rock to bedrilled, rotary motor means for imparting said rotary movement andmounted on said support means for movement with said percussive motormeans, a driving chuck coaxially aligned with said percussion motormeans and in driven engagement with said rotary motor means to berotated thereby, a drill rod and tube connecting adapter releasablyengaged in said chuck but for axial movement with respect thereto, meanson said adapter for receiving and transmitting axial percussive forcesfrom said percussion motor means, additional means on said adapter inrotary driving engagement with said chuck for transmitting therefromsaid rotary movement, first threaded connecting means on said adapterfor engaging one end of said drill rod and for imparting rotary movementthereto, abutment surfaces on said adapter and substantiallyperpendicular to the axis thereof for directly transmitting percussiveforces to said drill rod independently of said threaded connectingmeans, second threaded connecting means on said adapter for engagingsaid drill tube and for imparting said rotary movement thereto, andadditional abutment surfaces on said adapter for directly transmittingpercussive forces to said drill tube independently of said threadedconnecting means, said second threaded connecting means being disposedcoaxially around said first threaded connecting means and said drill rodand including means for disengaging said drill tube from said adapterfor retracting and withdrawing said drill rod and said adapter from saiddrill tube.

2;. Apparatus as recited in claim 1 in which said drill rod and saiddrill tube each comprises a plurality of interconnected axiallyextending segments successively joined together in end-to-end relation,and joining means for joining said segments together in said end-to-endrelation.

3. Apparatus as recited in claim 2 which also includes a plurality ofthreaded sleeves for joining said segments of said drill rod and saiddrill tube, said threaded sleeves engaging correspondingly threaded endsof two adjacent segments forming connections therebetween fortransmitting said rotary movement, and adjacent said segments eachincluding abutment surfaces substantially perpendicular to the axis ofsaid segments and in direct abutting engagement for transmittingpercussive forces from .one said segment to the next substantiallyindependently of said sleeves, the outside diameter of said sleevesinterconnecting segments of said drill rod being less than the insidediameter of said drill tube segments.

4. Apparatus as recited in claim 1 which also includes hoist meansoperating on said support means and operating independently of saidmotor means thereon for engaging and retracting said drill tube whendisengaged from said adapter.

5. Apparatus as recited in claim 4 in which said hoist means includes aslide member on said supporting means for engaging the upper end .ofsaid drill tube when disengaged from said adapter.

6. Apparatus as recited in claim 1 in which all the elements recitedtherein are supported on a moveable carriage and including means forselectively positioning said supporting means for addressing said earthcovered rock to be drilled at a variety of positions.

7. In apparatus for drilling in earth covered rock with both a hollowdrill tube and a drill rod coaxially operating within said drill tube,both said drill tube and said drill rod comprising a plurality ofsegments, and including motor means for driving both said drill tube anddrill rod for both rotary and axial percussive drilling movements, thecombination which comprises chuck and adapter means for transmittingboth said rotary and axial percussive movements to said drill tube anddrill rod and for releasably and independently connecting said drilltube and drill rod into driving engagement with said motor means, saidadapter means including releasable threaded connections for separatelyengaging said drill tube and drill rod and for transmitting said rotarymotion thereto, cooperating abutment surfaces on said adapter means andsaid drill tube and said drill rod substantially perpendicular to theaxes thereof and disposed in direct abutting relation when said drilltube and said drill rod are engaged by said threaded connections fortransmitting said axial percussive movement from said adapter meansdirectly to said drill tube and drill rod through said abutment surfacesand substantially independently of said threaded connections, and meansfor advancing and retracting said chuck and adapter means axially ofsaid drill tube and drill rod, said threaded connection and abutmentsurfaces for said drill rod all being configured and disposed coaxiallywithin said drill tube and said threaded connection and abutmentsurfaces thereof whereby axial advancing and retracting of said drillrod may occur within said drill tube and independently thereof when saiddrill tube is disengaged from said adapter means yet whereby both rotaryand percussive drilling movements are transmitted simultaneously to bothsaid drill tube and said drill rod whenever both are engaged with saidadapter means.

8. Apparatus as recited in claim 7 in which said drill tube and drillrod each comprises a plurality of axially extending segments joined inend-to-end arrangement, and a plurality of threaded sleeve connectorsfor joining said segments in said end-to-end arrangement, and in whicheach of said segments includes abutment surfaces substantiallyperpendicular to the axis thereof and in direct abutting relation fortransmitting axial percussive forces from one said segment to the nextsubstantially independently of said sleeve connectors.

9. Apparatus as recited in claim 7 in which said threaded connection forengaging said drill rod with said adapter means includes an axialthreaded recessin the lower end of said adapter means for receiving saiddrill rod therein, and in which said threaded connection for said drilltube includes a threaded sleeve around said adapter means for receivinga threaded end of said drill tube therein, and in which said abutmentsurfaces for transmitting said percussive forces are formed at the upperend of said threaded recess for said drill rod and in the upper portionof said threaded sleeve for said drill tube.

10. In apparatus for drilling in earth covered rock with both a hollowdrill tube and a drill rod coaxially operating within said drill tubeand having a driving chuck and motor means for driving both said drilltube and drill rod for both rotary and axial percussive drillingmovements, a connecting adapter assembly for releasably connectingsuccessive drill tubes and drill rods separately into driving engagementwith said drive chuck and motor means, which comprises in combination ashank portion on said adapter for releasably engaging said chuck forsubstantial axial movement with respect thereto during said percussivedrilling movements, means on said shank portion forming a drivingengagement with said chuck for rotary driving movement therewith, a bodyportion on said adapterfor receiving said drill tubes and drill rods,first connecting means adjacent the axis of said body portion forengaging one end of a drill rod therein for transmitting rotary movementto said drill rod, an annular abutment on said body portionsubstantially perpendicular to the axis thereof and adjacent saidconnect ing means for directly engaging cooperating abutment surfaces onsaid drill rod for transmitting axial percussive forces directly theretoand independently of said connecting means, second connecting means onsaid body portion and disposed coaxially around said first connectingmeans and said drill rod for engaging one end of a drill tube thereinfor transmitting rotary movement to said tube, and an annular abutmenton said body portion and said second connecting means and substantiallyperpendicular to the axis thereof for directly engaging cooperatingabutment surfaces on said drill tube for transmitting axial percussiveforces directly thereto, the lower ends of said drill tube including anannular percussion drill bit for drilling a hole of at least as great adiameter as said drill tube and the lower end of said drill rodincluding a percussion drill bit for drilling a hole of a diameter atleast as great as said drill rod, with the diameter of said drill rodbeing substantially as great as the internal diameter of said annulardrill bit on said drill tube.

11. Apparatus as recited in claim 10 in which said first connectingmeans for said drill rod includes an axial recess in said body portionfor receiving said drill rod therein and including said abutmentdisposed for directly engaging the upper end surface of said drill rod,and in which said second connecting means comprises an internallythreaded sleeve in threaded engagement with said body portion and aroundthe outside thereof for receiving the upper end of said drill tube andhaving a radially inwardly extending annular abutment directly engagingsaid body portion and the end surface of said drill tube for providingsaid direct transmission of percussive forces.

References Cited by the Examiner UNITED STATES PATENTS 1,079,836 11/1913Canfield -320 X 1,507,986 9/1924 C-avender 175-320 X 1,628,033 5/1927Davis 175-320 X 1,882,906 10/1932 Renfer 1 175-405 X 2,292,867 8/1942Charles 175-138 X 2,536,971 1/1951 Weyandt 175-138 2,598,454 5/1952Smith 175-138 X 2,599,770 6/1952 Marcerou 175-403 X 2,684,229 7/1954Bergstrom 175-171 X 2,701,122 2/1955 Grable 175-69 2,784,942 3/1957'Peck et al 175-171 2,830,795 4/1958 Center 175-379 2,903,242. 9/ 1959Bodin'e 175-404 X 2,948,514 8/1960 Long 175-171 X 3,023,820 3/1962Desvaux et al. 175-171 X CHARLES E. OCONNELL, Primary Examiner.

1. IN APPARATUS FOR DRILLING IN EARTH COVERED ROCK WITH BOTH A HOLLOWDRILL TUBE AND A DRILL ROD COAXIALLY OPERATING WITHIN SAID DRILL TUBEAND WITH BOTH SAID DRILL TUBE AND DRILL ROD BEING DRIVEN FOR BOTH ROTARYAND AXIAL PERCUSSIVE DRILLING MOVEMENT,S THE COMBINATION WHICH COMPRISESPERCUSSION MOTOR MEANS FOR PROVIDING SAID AXIAL PERCUSSIVE DRILLINGMOVEMENT, MEANS FOR SUPPORTING SAID MOTOR MEANS FOR AXIAL ADVANCING ANDRETRACTING MOVEMENTS TOWARD AND AWAY FROM SAID EARTH COVERED ROCK TO BEDRILLED, ROTARY MOTOR MEANS FOR IMPARTING SAID ROTARY MOVEMENT ANDMOUNTED ON SAID SUPPORT MEANS FOR MOVEMENT WITH SAID PERCUSSIVE MOTORMEANS, A DRIVING CHUCK COAXIALLY ALIGNED WITH SAID PERCUSSION MOTORMEANS AND IN DRIVE ENGAGEMENT WITH SAID ROTARY MOTOR MEANS TO BE ROTATEDTHEREBY A DRILL ROD AND TUBE CONNECTING ADAPTED RELEASABLY ENGAGED INSAID CHUCK BUT FOR AXIAL MOVEMENT WITH RESPECT THERETO, MEANS ON SAIDADAPTER FOR RECEIVING AND TRANSMITTING AXIAL PERCUSSIVE FORCES FROM SAIDPERCUSSION MOTOR MEANS, ADDITIONAL MEANS ON SAID ADAPTER IN ROTARYDRIVING ENGAGEMENT WITH SAID CHUCK FOR TRANSMITTING THEREFROM SAIDROTARY MOVEMENT, FIRST THREADED CONNECTING MEANS ON SAID ADAPTER FORENGAGING ONE END OF SAID DRILL ROD AND FOR IMPARTING ROTARY MOVEMENTTHERETO, ABUTMENT SURFACES ON SAID ADAPTER AND SUBSTANTIALLYPERPENDICULAR TO THE AXIS THEREOF FOR DIRECTLY TRANSMITTING PERCUSSIVEFORCES TO SAID DRILL ROD INDEPENDENTLY OF SAID THREADED CONNECTINGMEANS, SECOND THREADED CONNECTING MEANS ON SAID ADAPTER FOR ENGAGINGSAID DRILL TUBE AND FOR IMPARTING SAID ROTARY MOVEMENT THERETO, ANDADDITIONAL ABUTMENT SURFACES ON SAID ADAPTER FOR DIRECTLY TRANSMITTINGPERCUSSIVE FORCES TO SAID DRILL TUBE INDEPENDENTLY OF SAID THREADEDCONNECTING MEANS, SAID SECOND THREADED CONNECTING MEANS BEING DISPOSEDCOAXIALLY AROUND SAID FIRST THREADED CONNECTING MEANS AND SAID DRILL RODAND INCLUDING MEANS FOR DISENGAGING SAID DRILL TUBE FROM SAID ADAPTERFOR RETRACTING AND WITHDRAWING SAID DRILL ROD AND SAID ADAPTER FROM SAIDDRILL TUBE.